Human stem cells add a tremendous power to cell-based drug discovery assays. This potential stems from their unique properties that include self-renewal and differentiation potential. Efforts related to drug discovery that use stem cell have been mainly focused on two areas: 1) toxicology studies and 2) discovery of new drugs and targets for tissue regeneration and cancer treatment.
Despite their potential and the current research efforts, stem cells are underutilized in this field due to the inexistence of stable stem cell lines capable of growing indefinitely and showing a reproducible behavior in culture. Furthermore, normal human primary stem cells are niche dependent and cannot be passaged as single cells, which consequently disables robotic seeding/passaging of cells and large-scale cell culture preventing their use in high-throughput screening assays. Accordingly, there is a need for novel stem cells and associated assays that meet the needs of high throughput assays.
In addition, cancer and normal stem cells (SCs) share proliferative properties of self-renewal and expression of key transcription factors (TFs). Despite similar TF identities, the functional role of specific TFs responsible for retaining SC state has not be carefully examined in cancer. There is also a need for new models for the study of cancer stem cells as well as methods and assays for selectively targeting cancer stem cells without damaging normal stem cells.